This invention relates generally to chains and more particularly to chain assemblies having replaceable plug-in modules.
Pertinent United States and foreign patents are found in Class 59, subclasses 78.1 and 93, and in Class 198, subclasses 648, 651 and 652 of the Official Classifications of Patents in the United States Patent and Trademark Office.
Examples of pertinent patents are U.S. Pat. Nos. 1,707,088; 4,129,206; 3,344,904; 3,365,158 and 3,915,288.
U.S. Pat. No. 1,707,088 shows an article support pin attached through a chain link and riveted in place on the chain. U.S. Pat. No. 4,129,206 shows a pin having a rotatable sleeve attached to the pin by a socket means. When damaged, the sleeve is easily removed and replaced while the pin remains attached to the chain.
U.S. Pat. Nos. 3,344,904 and 3,365,158 show pins, each having a shoulder which abuts the outer surface of the chain and a reduced, threaded portion which extends through to the inner surface of the chain. A nut is threaded onto the reduced portion of the pin to secure the pin to the chain. U.S. Pat. No. 3,915,288 shows a sleeve similar to those of U.S. Pat. Nos. 3,344,904 and 3,365,158.
U.S. Pat. Nos. 2,565,593; 788,542; 3,166,103; 3,086,641; 3,206,0041 3,206,0051 3,770,1071 3,387,829 and 3,625,338 are also pertinent to the state of the art in attaching pins to chain link systems.
Chains with extended pins or other attachments are known in the art. However, frequently, the extended pins or other attachments are damaged while in use. It is therefore highly desirable that the extended pins or attachments be quickly and easily removable and replaceable. Previous chain assemblies have proven unsatisfactory in this regard because they require disconnection of the chain to remove the attachments.